An improved articulated model of the human hand

We present an improved anatomically based approach to modeling the human hand for use in the animation of the American Sign Language. The joint rotations in the model are based on the bone and muscle configurations of the hand, and a forward kinematic solution is used to position the hand. In particular, we investigate the rotations of the base joint of the thumb. This joint is a saddle joint with nontrivial rotational axes and centers, and must be treated with care in such a model. We take advantage of several correlations between joint rotations in the hand to reduce the number of degrees of freedom in the model and to provide a simple, natural, and interactive interface for American Sign Language handshape transcription.